In a mixing bowl, whisk together the sugar, cocoa powder, and salt. Set aside.

Fill a medium pot halfway with water. Bring the water to a simmer over low heat.

Place a heat-safe bowl (glass or stainless steel) that can just fit on top of the pot of simmering water, but leaves a gap between the water and bottom of the bowl.

Add the chocolate chips to the bowl. Keep the heat on low and use a rubber spatula to stir the melting chocolate chips until smooth. Remove the bowl of chocolate, but leave the water in the pot to be used later.

Add a heaping spoonful of the melted chocolate to each of the six chocolate molds. Use the spoon to spread the chocolate up the sides of each mold. Make sure the entire inside of each mold is evenly coated with chocolate. (Save extra chocolate to use later.)

Freeze the chocolate for 10 minutes, or until completely set.

Line a baking sheet with parchment paper.

Once set, carefully remove the chocolate cups from the mold, placing them on the lined baking sheet.

Flip over three of the molds to be filled. Fill each of the 3 halves with 2 tablespoons of hot cocoa mix, 1 tablespoon of crushed peppermint candies, and 5-6 mini marshmallows.

Place the other three halves, seam-side down, on a separate baking sheet. Place the sheet on top of the pot of warm water over low heat to slightly melt the rims of the molds.

With gloves on (so you don't leave fingerprints) cover each filled chocolate half with an empty half, sealing it.

Decorate with any extra melted chocolate, remaining candies, sprinkles, and other candies. Use immediately, or within 24 hours, for best results. Store at room temperature.

To make hot chocolate, add a peppermint hot cocoa bomb to a mug. Slowly pour about 1½ cups of hot milk or hot water over the bombs and stir. (Pour some hot coffee over the bomb for a peppermint mocha.) Sip and enjoy!